Just put some 255/40/17s on my rear coming from 245 squared ( all Hankook v12s ) Previous rear set of tires wore unevenly so I figured it was time for an alignment after this set I just put on . Went for a quick drive after putting the new set on and I instantly had no confidence driving this car . The car swayed like ive never experienced before when accelerating in corners and also when letting off . So is this just me needing an alignment or is this how going to such a meaty setup changes the car? Or is it because I’m staggered now ? Or is the obvious alignment needed. The only reason I’m even asking this is because on the previous square 245 set up from the tire wear I guess I needed an alignment pretty bad but the car never felt like it . I could throw it through the mountains and it was a planted go kart. After putting on these 255s I wouldn’t feel confident going 45 in a corner lol.

 

Also my wheel specs are 17x9 + 40 squared

 

There are two possibilities.

1. Rear tire circumference

Either because:

A. The tire pressures aren't exactly the same left to right in the rear

B. The tires aren't from the same manufacturing batch and are slightly off on actual physical size due to manufacturing tolerances.

Neither of these would be a problem on most any other car. But the S is hyper sensitive to rear tire circumference.

2. An alignment problem

My guess is it's 1A. But I guarantee you it is one of the reasons above. Its not due to upsizing to 255. Its not due to stagger.

 

alright going to go check/adjust my tire pressure. For street use about 32 psi is good all around correct ?

 

OP said his tires did not wear evenly without details. This could be a helpful diagnostic tool. What do you mean when you say they did not wear evenly?

 

the wear was relatively close but the right for sure had more wear and it’s also a slight visual noticeable difference in camber or toe maybe on that side but it never effected handling . It was more so just an eye sore to me. If it’ll help hear is the right wire down tire

 

Also just checked the air pressure rears were both 32-34ish fronts were low at about 24 now they’re 32 . Maybe all 4 tires were low so when the new full 32 psi rear tires were added it threw balance off lol idk . Gonna go for a quick test drive again , but I’m still aware I need an alignment for sure

 

Yea, these cars need to have good alignments and good tire pressure. If they have that they are wonderful. My right rear always wears faster than the left rear. Looks like you got your money out of that tire.

 

IIRC, a few people who have installed V12's have had this issue.

Its probably just a ton of tread squirm when the tires are new.

Try an alignment to see if it helps, OP.

Otherwise, you'll need to wait until the tires wear a little.

 

sounds good